Feat/prerequisites warning

[Duy-Nguyen1104]

Description

(The PR contains commit for previous PR as it has not been merged yet)

(The PR assumes that the backend has added features from this PR: thoth-tech/doubtfire-api#71)

This PR implements comprehensive prerequisite validation for the course map feature, ensuring that units with prerequisites are properly validated when placed in study periods. The validation system provides real-time warnings when prerequisite requirements are not met.

Features Added

1. Prerequisite Validation Service

• New Service: PrerequisiteValidationService
• Validates unit placement against prerequisite requirements
• Checks that prerequisites are placed in previous trimesters (not same trimester)

2. Visual Warning: Unit Card with prerequisite warnings

3. Validation Rules Implemented

• Prerequisites must be completed in previous trimesters (not same trimester)
• Missing prerequisites trigger warnings

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Manual Testing Scenarios

• Place a unit with prerequisites → warnings appear if prerequisites missing
• Place prerequisites after dependent units → warnings on both units
• Move units around → validation updates in real-time
• Place prerequisites in same trimester → appropriate warnings shown
• Complete valid progression → no warnings displayed

Testing Checklist:

• Tested in latest Chrome
• Tested in latest Edge

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code in hard-to-understand areas
• My changes generate no new warnings

[giangnht19]

Hi @Duy-Nguyen1104, the feature is well-structured and the rules are clearly enforced. I like the real-time warnings on unit cards, that’s going to make the course map much more user-friendly. Thanks for covering the edge cases around same-trimester prerequisites. Approved !